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N0'M0de1.) G; O. BER-GSTROM.

HOT AIR FURNACE.

No. 575,766. Patented Jan. 26,1897. Tigfl- 5 TIECH- all! jd z w 1 W GEUIHE' ELBEYBSTFDITL By his Any gi UNITED STATES PATENT OFFICE.

GEORGE O. BERGSTROM, OF NEENAH, WVISCONSIN, ASSIGNOR TO BERGSTROM BROS. ((6 00., OF SAME PLACE.

HOT-AIR FURNACE.

SPEGIFIGATION forming part of Letters Patent No. 575,766, dated January 28, 1897. Application filed November 13, 1896. $erial No. 611,990. (No model.)

To all whom, it may cancer/1.:

Be it known that I, GEORGE O. BERGSTROM, a citizen of the United States, residing at Neenah, in the county of Winnebago and State of \Visoonsin, have invented a new and useful Improvement in Hot-Air Furnaces, of which the following is a specification.

My invention relates to the form and arrangement of the several parts of the fur- 1o nace whereby a large surface is presented from which the heat which is producedby the burning fuel can be radiated and against which surface also a large body of fresh cold air may be presented to be warmed and distributed to the several apartments which it is desired to warm; and the object of my im-' provement is to produce a furnace having, in comparison with the amount of fuel burned, a large heating capacity. I attain this pur- 2o pose by means of the construction and arrangement of parts illustrated in the accompanying drawings, in which Figure 1 is a side elevation of the furnace, the larger part of its outer wall or casing be- 2 5 ing broken away for the purpose of exposing the inner parts. Fig. 2 is a top view of its upper radiator. Fig 3 is a transverse section of one of the radiators midway its ends. Fig. 4 is an elevation of the front end of the heating parts with the f urnace-front removed,

and Fig. 5 is an elevation of the furnacefront upon an enlarged scale.

Similar numerals and letters indicate like parts in the several views.

3 5 1 indicates the f urn-ace-front 2,doors which communicate with the radiator.through which they can be cleaned; 3, the fuel-door; 4, ashpit door; 5, the ash-pit; 6, the fuel-receptacle or fire-pot; 7 7', radiators; 8 8 8", short 1 4o pipes for connecting the fire-pot to a radiator which is adapted for connecting the fire-pot and radiators when they are arranged in their proper position, and which is suited for connection with the inclosing wall or casing 12. The fire-pot 6 consists of a box-like inclosure having greater length than breadth or height,

a suit-able bottom a, a rear end Z), its top 0, and sides d.

The top of the fire-pot is an oval-shaped casting and extends from the front 1 to the rear end 17, and the sides cl consist of oval plates having corrugations e transversely thereof over their entire length. These corrugations are not a new invention, but are an important feature, as they add to the last- 6 5 ing quality of the fire-pot by reason of said corrugations absorbing the extension and contraction of the metal as the heat is increased or diminished without causing the plates to crack.

The rear end I) of the fire-pot extends back a few inches beyond the ends of the sides d and from the pipe 8, where the heat from the fire-pot escapes, whereby the intensity of the heat upon said rear end is reduced. This eX- tension, together with the aforesaid corrugations, gives a large radiating-surface for the fresh air to impinge against and be heated.

Directly over and lying parallel with the fire-pot are two radiators 7 7, which have greater length than breadth and are similar one to the other excepting in their heat receiving and discharge openings. They are formed of two corresponding parts h and i, which are connected together with bolts f. 8 5 These radiators need not be of the exact form here shown, as radiators having the essential features of these of different form may be used. The number of radiators in any one furnace may be more or less than is here shown, they being so arranged relative to the fire-pot that all of the heat from said fire-pot will pass through their entire length and that their openings g will be free to receive the fresh or cold air which is to be warmed and 5 distributed to the several rooms to be warmed.

A short pipe 8 connects the fire-pot and lower radiator, and a pipe 8 connects the two radiators at their rear end, and a pipe 8" connects them at their front end.

The pipe 8 is provided with a damper, its arm 9 being connected to a rod 10, which exlOO tends through the furnace-front and from which point it can be operated. With this damper open the heat and smoke will pass from the fire-pot through the pipe 8, thence directly through the radiator 7 to the pipe 8 and radiator 7 and out through the smokeoutlet, but with said damper closed the heat and smoke will pass through the radiator 7 to its forward end, thence through the pipe 8 to the radiator 7, back through it and out of the pipe 11, and thereby imparting to the entire interior surface of both radiators the benefit of all of the heat from the fire-pot. This damper needs to be open only in starting the tire.

The radiators are open at their forward end, and their end flanges 7c are bolted to the front 1, doors 2 being provided for closing said opening, upon the opening of which doors access is obtained to their interior, and the attendant with a scraper can scrape all soot and ashes to their rear,where they will fall through the pipes S 8 into the fire-pot and from whence they can be removed through the ashpit door 4.

The inelosing wall 12 may be of brick or metal, as the particular use and location of the furnace may require, said wall being provided with a sufficient number of fresh-airsupply and warm-air-discharge pipes or openings, the latter being from the top of said casing, as shown at the right, or, a cover 15 being provided for said casing, it may be from the left-hand side of said casing or wall.

Having described my invention, what I claim, and desire to secure by Letters Patent,

1. In a hot-air furnace the combination of the following instrunientalities, a furnacefront having suitable doors for feeding fuel thereto and for removing soot and ashes therefrom, a wall, or case connected with said front and inclosing the fire-pot and radiators and being provided with suitable freslraiwsuppl y and warni-air-distributing openings, a firepot connected to said front consisting of an inclosure having greater length than breadth and having a longitudinally-oval-shaped top and sides, the latter having aseries of corrugations transversely thereof over their entire length, two radiators having greater length than thickness arranged one over the other over said fire-pot, each having an open space midway its ends and sides extending through the same in the direction of said thickness, one end of said radiators being open, connected to said front around a door therein, and said 'adiators extending at right angles with said front over said fire-pot, openings near each end of said radiators for the admission of the products of combustion from the fire-pot and for the escape of the same, connecting-pipes arranged, one for connectin the two radiators near their forward end, one between the fire-pot and lower radiatornear their rear end, and one directly over the last-named pipe for connecting the'radiators one to the other, said last-named pipe having a damper therein which when closed will direct the products of combustion as they leave the fire-pot and enter the lower radiator toward the f urnaee-fron't, thence upward to the upper radiator and toward its rear end and out of the smoke-pipe, substantially as described.

2. A radiator for a hot-air furnace consistin g of an inelosure having greater length than thickness, and having an open space midway its ends and sides extending through the same in the direction of said thickness for the circulation of air through said space, one end of the radiator being open and fitted for connection with the furnace-front around an opening therein which is adapted for closure at will, said radiator being provided with openings near each end thereof for the admission of the products of combustion from the fire-pot and for the escape of the same, substantially as set forth.

3. In a hot-air furnace, the combination with the fire-pot of a plurality of radiators arranged one over the other, over said firepot, and being open at one end and adapted for connection with the f urnace-front at right angles with it and around an opening therein which is adapted for closure at will, said radiators having greater length than thickness and each having an open space midway its ends and sides extending through the same in the direction of said thickness for the circulation of air through said space, a pipe leading from the fire-pot to the lower radiator at its rear end, pipes COnHGCtlHfI the radiators at each end thereof, a damper in their connecting-pipe at their rear end having means for its operation, whereby, the damper being open the products of combustion will pass from the fire-potinto and across the radiators and thence out of the smoke-pipe, but it closed will pass through the length of all of said radiators before its escape through the smoke-pipe, substantially as described.

GEORGE O. BERGSTROM. Vitnesses:

JOHN MAYER, JOHN C. WALLEY, 

